1. Field of the Invention
This invention relates to a stiff supporting bandage, which is light in weight, high in rigidity and strength and which is suitable to cover, set, protect and re-form a damaged member including bone fractures, dislocations, sprains or deformations in humans as well as in animal bodies.
2. Prior Art
Stiff supporting bandages incorporating cloth and plaster of Paris are well known. The powder of plaster of Paris, dosed with a viscosity promoter, an endosmotic agent and a solidifying rate adjuster, is made into a powder, or into a suspension within an insoluble liquid. This compound is then coated onto or impregnated into cotton cloth or a basic fabric. The coated or impregnated fabric is then formed into a roll or a pile of sheets for general use. Stiff supporting bandages, wherein plaster of Paris is utilized as solidifiable material, are very high in rigidity, and are easily modeled to accommodate the damaged member or any irregularity thereof. Such bandages, however, have drawbacks. These include, weighing too much, being brittle, having poor permeability to X-rays and being easily stained.
Solidifiable resins which provide an alternate to plaster of Paris are available whose rigidity is sensitive to light, heat or catalytic agents. A suitable photo-solidifiable resin consists of unsaturated polyester and a sensitizer; suitable thermo-plastic resins include caprolactone, ethylene vinyl vinylchloride copolymer, and transtype polyisoprene. Suitable reactable resins consist of polyurethane resin and isocyanide, or polyacrylic acid and dimetallic salt. A solidifiable resin as disclosed above may be applied to a basic fabric consisting of woven or knitted cotton fibre or glass fibre. The treated fabric may then be formed into a roll or a pile of sheets. A stiff supporting bandage utilizing one of the above listed resins and a fabric formed of cotton or glass fibres is considerably improved in weight, stain resistance, ventilability, and X-ray permeability.
However, a fabric consisting of glass fibres alone has been found to be incapable of retaining a sufficient amount of solidifiable material. The surface smoothness of the glass fibres limits the amount of solidifiable material retainable by the fabric. Consequently, such a bandage would need to be wound in 8 to 10 layers to produce the necessary strength and rigidity. The added layers of bandage increase the cost, require excessive time to apply and are a great burden for the patient. Because of poor adhesiveness between the glass fibres and the solidifiable material it has been found that, if the protected portion suffers an impact after the solidifiable material has set, it could easily crack.
On the other hand, a basic fabric formed of cotton, flax, staple fibre, rayon, wool, acrylonitrile, nylon, polyester or the like, readily retains adequate solidifiable material. Bandages utilizing these fabrics have the disadvantages of an insufficient setting force and too high an elasticity. As a result, it is difficult to hold the damaged member precisely in a stiffened state. This limitation results in a very narrow range of application of these bandages. There has thus been an unfilled need for an improved fabric usable with the above identified resins and other solidifiable materials.